{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\r\n\tBeing the only living descendant of his grandfather, \u003cspan data-scayt_word\u003d\"Kamran\" data-scaytid\u003d\"1\"\u003eKamran\u003c/span\u003e the Believer inherited all of the grandpa\u0026#39;s belongings. The most valuable one was a piece of convex polygon shaped farm in the grandpa\u0026#39;s birth village. The farm was originally separated from the neighboring farms by a thick rope hooked to some spikes (big nails) placed on the boundary of the polygon. But, when \u003cspan data-scayt_word\u003d\"Kamran\" data-scaytid\u003d\"2\"\u003eKamran\u003c/span\u003e went to visit his farm, he noticed that the rope and some spikes are missing. Your task is to write a program to help \u003cspan data-scayt_word\u003d\"Kamran\" data-scaytid\u003d\"3\"\u003eKamran\u003c/span\u003e decide whether the boundary of his farm can be exactly determined only by the remaining spikes.\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\r\n\tThe first line of the input file contains a single integer t (1 \u0026lt;\u003d t \u0026lt;\u003d 10), the number of test cases, followed by the input data for each test case. The first line of each test case contains an integer n (1 \u0026lt;\u003d n \u0026lt;\u003d 1000) which is the number of remaining spikes. Next, there are n lines, one line per spike, each containing a pair of integers which are x and y coordinates of the spike.\u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\r\n\tThere should be one output line per test case containing YES or NO depending on whether the boundary of the farm can be uniquely determined from the input.\u003c/div\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e\r\n1\r\n6 \r\n0 0\r\n1 2\r\n3 4\r\n2 0\r\n2 4 \r\n5 0\r\n\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e\r\nNO\u003c/pre\u003e"}}]}